1. Field of the Invention
This invention relates to a steering assembly for a vehicle, and more particularly to an energy absorbing steering assembly for protecting a driver which is collapsible and absorbs the energy when a vehicle impacts on an obstacle.
2. Description of the Prior Arts
A conventional energy absorbing steering assembly, for example, U.S. Pat. No. 3,262,332 issued to Robert D. Wight comprises a steering gear box fixed to a vehicle, a telescopeable steering shaft assembly connected at one end to said gear box and having a steering wheel mounted on the other end thereof, an intermediate column surrounding said shaft assembly and rigidly connected to said vehicle, and energy absorbing means interposed between said shaft assembly and said column operative to impact controlled resistance to telescoping movement of said shaft assembly in either direction.
U.S. Pat. No. 3,373,629 issued to Robert D. Wight et al. discloses an energy absorbing mesh portion constructed of a network of intersecting and interconnected strips directed angularly of the axis of the steering column. The network provides the diamond shape perforations in the flat stock of the mast jacket before forming it into a cylinder.
U.S. Pat. No. 3,392,599 issued to Robert L. White discloses a device for absorbing the kinetic energy of impacts comprises a pair of members arranged for movement relative to each other upon the application of impact force thereto, and a rolling body engaged between two membes with predetermined interference fit and having portions formed for localized contact therewith. The interference fit of such degree as to effect predetermined localized plastic deformation along a path of travel in at least one of said members as the rolling body rolls due to relative movement therebetween thereby to absorb the energy of the movement. In this patent the rolling body is always engaged between two members with predetermined interference fit, which requires a precise finish working.
U.S. Pat. No. 3,373,630 issued to Byron T. Heurtebise describes a telescopic steering column assembly in which one or more of the column members thereof is constructed and arranged to readily structurally deform under impact loading thereon and absorb the energy of the impact.
As above described, there are various kinds of energy absorbing means to absorb the energy of the impact force, however, these means require expensive manufacturing costs.